


Not about Number Theory

by oswin42



Category: Sherlock (TV)
Genre: Alternate Universe - College/University, Fencing, Gen, Mathematics, Platonic Relationship, Student!Jim, Tags to be added, Uni AU, professor!mycroft, there's no romance or sex
Language: English
Status: Completed
Published: 2017-02-06
Updated: 2017-09-14
Packaged: 2018-09-22 11:23:56
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 21
Words: 12,095
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9605708
Author URL: https://archiveofourown.org/users/oswin42/pseuds/oswin42
Summary: Mycroft Holmes, professor in Pure Mathematics, starts tutoring a new student called Jim Moriarty. Jim Moriarty is young, cocky and absolutely brilliant. Mycroft Holmes starts to figure out that they have more in common when he runs into his new student at his fencing club. Jim Moriarty, next to his study and his job, is trying to build up a criminal empire.What happens when these two brilliant minds meet and start to figure out who the other really is?-existing chapters edited to be easier to read-





	1. Chapter 1

**Author's Note:**

> I was lacking inspiration for "A glimpse into the interaction between Jim Moriarty and Mycroft Holmes" and asked for a prompt or idea. A good friend who goes by Madlockian suggested I should try to write an Uni AU for it. The story got a little out of hand and I decided it would be a fun fic to post while writing.

Jim Moriarty, barely 18 years old with messy short hair, glasses, wearing a dress shirt and a leather shoulder bag over one shoulder, sprinted through the university square. He only just took time to avoid the grass as he did not want to get into more trouble. He stopped just before his tutors office and straightened his clothes and hair. He checked his watch and was relieved to find he was only one minute late. Even so, being late for your first appointment with your tutor wasn’t exactly going to give a good impression. He took a deep breath and knocked on the wooden door.

“Come in.” came a smooth, educated voice.  
Jim opened the door and stepped in. Professor Holmes sat behind his desk reading the essay Jim had submitted with his application. The professor was dressed rather formally in a grey tailored three-piece suit with a matching tie. He had an slightly unimpressed expression on his face but Jim could see that his professor was intrigued by his essay.  
“How good of you to finally show up, mister Moriarty. Please, sit.” the professor said rather coldly. Jim dropped his bag down next to the chair and sat down.  
“My apologies, professor.” He said as he dug his notebook out of his bag.  
Mister Holmes looked at Jim over his paper. “Not going to try to make excuses?”  
“I don’t see why, professor.” Jim said as he searched for the right page. “As you pointed out I was late and you deserve an apology for that, not an excuse.”  
Mister Holmes smiled approvingly, but didn’t comment on it further. “Why don’t you start by telling me some things about yourself, young man?”  
Jim sat up straighter “I’m from Ireland originally, but I’ve lived in England for years now. I work in a second hand bookstore, I take MMA and fencing and I read a lot.”  
Professor Holmes raised an eyebrow. “And academically?”  
“I supplied all the papers.” Jim replied instead of answering the question.  
“I’d like to hear it from you.”  
“I was allowed to work at my own pace in school and went through the years rather quickly. I aced all my exams, taught other kids in school.” he shrugged.  
“You’ve been done for two years and your old school has informed me you were a trouble maker.”  
“Yet you agreed to be my tutor.”  
Mister Holmes grinned “I have a reputation as well. Why the two year gap?”  
“I needed to save up, Mister Holmes. Now I have told you about myself, would you return the favour?” Jim asked with a cheeky smile.  
“Very well,” mister Holmes said “I graduated summa cum laude in pure mathematics and specialized in number theory, like you want to. I have a reputation for straightening out difficult students, but I think you are smart enough to know this already. Go on, mister Moriarty, impress me.”  
“You’re a fencer like me.” Jim started confidently, “you’re very clever and not above manipulating others, especially when you think it’s in the best interest. You have a lot more influence than most people think and you’re not above using that to your advantage. You could have won a Fields medal by now if you weren’t ‘branching out’. How am I doing, Mycroft?”  
While Jim had been talking Mycroft Holmes had gotten more guarded and closed off. Jim, in turn, had started grinning.  
“Care to explain your reasoning?”  
“Maybe another time.”  
Mycroft watched Jim carefully, taking his time reading him in return.  
“I can see this will be an interesting year, mister Moriarty. Let’s talk about your education.”

Jims brain was buzzing with ideas by the time he left the office of his tutor. This promised to be a very interesting year. He spent a couple of hours filing away ideas. He checked his email and replied to a few requests for consults. He wondered if professor Holmes had figured out his side business. He decided he would do a little digging on him for any potential dirt on his professor. He’d seen him fence with both the head of MI5 and MI6. He was pretty sure Mycroft Holmes did not know they shared a club since Jim kept a low profile on members’ nights. He’d won his place and was eager to keep it.


	2. Chapter 2

**Summary for the Chapter:**

> Jim meets his tutor again, this time at the fencing club.

He’d almost been late, having lost track of time when he was digging up information on his new tutor. He’d raced to the fencing club and locked his bike to a railing. He hurried inside and changed into his white fencing uniform. He put his clothes and bag into his locker before taking his epee out. He closed his locker and went out to one of the halls.

He was not surprised to see his tutor there. Mycroft Holmes was sat to one side and drinking tea with the president of the club. Jim nodded at the both of them out of respect and started his warming up. He could see the two of them from the corner of his eye and talking about him. He watched the president whisper to his instructor, who then came over and paired Jim up with a high class player. Jim straightened his back as he greeted to his opponent, then his instructor and finally to the president and Mycroft Holmes. He put his mask on and nodded.  
“Allez” came the voice of his instructor. The opponent attacked immediately. Jim, as he preferred, let the other attack once or twice before using one of his defensive moves and turning into a very effective counter attack.  
“Touch!” Called his opponent. They took a step back before Jim went right into the attack again and scored another point. Jim frowned. This player was supposed to be better than him, but he was almost easy. Perhaps, Jim thought, the man wasn’t used to playing against a left handed opponent. The opponent attacked first now, but Jim could hold himself to a decent standard while thinking.  
Jim observed the man. His legwork was near perfect and his moves were technically faultless but he struggled to keep up with Jim’s speed and moves.  
He’d scored four points by now and therefore he was only one point away from winning. Instead of trying to get fancy, he used a variation of the move he’d done before, the parry-reposte, and won.  
“Arrêt!” Called the instructor. Jim pulled his mask off and held out his hand for his opponent to shake. The man pulled his mask off and walked right by Jim, muttering angrily.  
“Well played.” Jim called after him with fake politeness.

Jim turned to Mycroft and the president of the club. He nodded at Mycroft in a polite greet, but at the same time a silent challenge. Mycroft whispered something to the president, the president called his instructor over and said something, and he in turn came to Jim “Mister Holmes would like to officially challenge you, Moriarty.”  
Jim grinned proudly. It was an honor to play against someone that high up in the club and winning could give him a lot more respect. Jim walked over to Mycroft. It was time to discuss the exact specifications.  
“Good evening, mister Holmes.” Jim greeted with a smile on his face.  
“Good evening, mister Moriarty.” Mycroft said with a lot less enthusiasm.  
“I gathered you’d like to fence against me, sir.”  
“That is correct.”  
“It is my understanding that, since you set the challenge, I get to pick the weapon.”  
“Correct again, mister Moriarty.”  
“I choose the epee, sir.” Jim had a cheeky smile on his face hidden under the politeness.  
“Very well. Would now be acceptable?”  
“That would be preferred, sir.”  
Now it was Mycroft’s turn to grin as he got up and retrieved his mask and epee. The middle of the hallway was cleared quickly.  
“Let's make this more interesting, shall we, mister Moriarty?”  
“What do you have in mind, sir?” Jim asked “I don’t have money to bet with.”  
“If you lose, you’ll tell me exactly how you got to all of your deductions.”  
“And if I win?” Jim asked curiously.  
“I most certainly doubt you will, but if you do, then I will introduce you as a member of the inner circle.”  
Jims eyes widened. The inner circle was very exclusive. He held out his hand “that’s a deal, sir.”

**Notes for the Chapter:**

> I tried to make the fencing sound as accurate as possible without getting too technical, since I tend to get too caught up in terms if I'm not careful.


	3. Chapter 3

**Summary for the Chapter:**

> Mycroft and Jim fence.

Mycroft shook Jim's hand before walking to the middle of the room. Jim took his place and checked his equipment. Mycroft, like Jim, preferred honesty and a judge over an electronic system.   
“Five points?” Mycroft asked. Jim nodded in reply as he put his sword up in greeting.   
“En garde.” Said the president. Jim put his mask on and nodded.   
“Pret”   
Jim got ready, standing with almost perfect posture and his epee in his left hand. Mycroft was close to a mirror image with his epee in his right hand.  
“Allez!” Called the president. 

For a few seconds they both stood, watching the other closely, before Mycroft attacked with several quick attacks that were mostly aimed on his backhand. Jim blocked every single one of them and, after getting up to speed with it, used the momentum to his advantage to counter with some quick and powerful replies. All of which Mycroft blocked. Then, all of a sudden, Mycroft slashed violently at Jim's arm and touched. Jim stepped back as both he and the president called ‘touch’. 

They both took a second before starting the attacks again. Mycroft scored his second touch quickly after the first, but Jim had spotted a weak spot in his backhand. Just a fraction of a second after his attack, but it was there, so when they started again Jim blocked strongly until Mycroft attacked with his backhand again and he took his chance.  
“Touch!” Called Mycroft with a clear smile in his voice. They went back to the fight almost immediately. Mycroft scored his third point then, hardly using his backhand. Jim then figured his best chance would be to score with a parry-riposte since the moment after his attack was the weakest moment. Jim started playing more and more defensively, but couldn't stop Mycroft from scoring his fourth point. They were both breathing fast now and it was very audible in the silent hall. Jim attacked a few times in quick succession and Mycroft blocked them all. Mycroft threw in a parry-riposte, which was exactly what Jim was hoping for. He used this moment to throw a fast hit at Mycroft and scored. 

It was now four to two for Mycroft and Jim knew he had very little chance to win it, but was determined to impress Mycroft and everyone else in the room. Mycroft started this time and seemed, to Jim, eager to end this game. He attacked quick and often, leaving little room for Jim to get any attacks in. But Mycroft was getting tired. Jim was in better shape and Mycroft made a mistake. Jim spotted it before Mycroft did and used the opening to lunge right at him.   
“Touch!” Mycroft said. 

Four to three now. Jim was catching up. His grin was hidden under his mask as he attacked viciously and quickly. He aimed to wear Mycroft out, to get Mycroft to make more mistakes, but as his mind ran the calculations on how long it would take Mycroft to start making more mistakes, he got distracted a moment too long and felt Mycroft's epee hit his arm.   
“Touch.” Jim called as he pulled off his mas. He had sweat on his face and his hair was much more messy than usual. He smiled as Mycroft pulled his mask off and looked equally tired. 

“Congratulations, mister Holmes.” Jim said with a soft grin. He’d enjoyed it massively and losing didn’t matter that much to him. Mycroft returned the grin.   
“Well played, mister Moriarty. I must admit you are better than I would have given you credit for.” Mycroft said with a rather amused smile, but Jim could see the metaphorical cogs turning in Mycroft's brain. Mycroft hid his coldness and worry expertly, but not good enough for Jim not to see it.   
“I believe you owe me an explanation, mister Moriarty.” Mycroft said “but I would prefer to freshen up, first. I’d suggest tea in, say, half an hour?”   
“That would be acceptable.” He agreed and walked to the student changing room. 

**Notes for the Chapter:**

> I hope all the fencing terms will make sense.


	4. Chapter 4

**Summary for the Chapter:**

> Tea and talking

Jim stood in front of the dark wooden door of the president's office 27 minutes later. He’d showered and tried to look more than somewhat representable. Half an hour was not enough time to cycle home, shower, change and cycle back so he had to make do with what he had. When he’d come back into the hall, the instructor had discreetly told him to head to the president's office. Jim knocked twice.   
“Come in James.” Mycroft said.   
Jim walked inside and looked around. The place hadn’t changed since the first time he’d been in there, with its dark wooden interior, swords on the walls and antiques as expensive as a flat in central London. He had been tempted more than once to steal one of the smaller items, ones that probably wouldn’t be missed for months, but Jim had a reputation of a good and honest hardworking kid and he wouldn’t jeopardize that reputation.   
“Professor.” Jim acknowledged with a smile as he came to a halt in front of the desk Mycroft was sitting behind.  
“Do sit down, James,” Mycroft said as he motioned at the chair, “and have a cup of tea.” He continued as he poured a cup of tea from an expensive China pot into a cup from the same set. Jim sat in the chair, his back straight and away from the seat and observed his professor. Mycroft Holmes was wearing a button up jacket with a high collar what, Jim assumed, was what he usually wore after fencing. His hair was still damp, much like that of Jim.   
“Thank you, sir.” Jim said as he took the cup from the saucer and took a sip. He recognized the tea as the one the president preferred and kept in his office. One that cost more per cup than some of his school books. 

“I believe you were going to tell me how exactly you knew all the information you so freely told me.”   
“I did lose the bet, yes.” Jim acknowledged.   
“Don’t let me keep you.” Mycroft said with a hint of annoyance in his voice.   
“That you are a fencer is rather obvious because I had seen you at the club before. I know of your influence because I have seen you fence and talk with some very influential names here and I have watched you play them like an instrument. I knew your first name because I heard one of them address you as such. Anything else?”  
“You suggested I could have gotten a Fields medal if I focused only on mathematics.”   
“I thought that one was rather obvious.”  
“I suppose it rather is. Are you disappointed you lost?” Mycroft asked somewhat more relaxed while sipping his own cup of tea.   
“I thought I played rather well.”  
“That is not what I asked.”  
“No, sir, I’m not disappointed. Are /you/ disappointed I managed to still score three points?”   
“I will admit I was surprised to see you adapt so quickly. I’m sure we shall play again sometime.”   
“Were you disappointed?” Jim insisted, just like Mycroft had.   
Mycroft smiled “just the opposite. I do enjoy a competent opponent.”   
“I shall try to be one.” Jim said with a grin.  
“I have no doubt about that.” Mycroft replied with a touch of coldness and worry in his voice.   
“Something on your mind, professor?”   
“I’d like you to listen carefully, James.” Mycroft said with cold eyes, but a polite face. “You’re a smart man with a lot of potential. If you do things my way you’ll be set in mathematics for the rest of your academic life. Possibly much more than just that. If, however, you decided to try and play against me you’ll find yourself on the losing side.”   
Jim smiled, with just a hint of a manic grin in it, “noted, professor. Anything else?”   
“I will see you at our appointment on Monday.”  
“Goodnight professor.” Jim said as he took the final sip from his drink, got up and left. 


	5. Chapter 5

**Summary for the Chapter:**

> A little bit of Jims life

It was six am on Saturday morning and his schoolwork had gotten him behind on his ‘other projects’ so much more than would have thought. This was mostly because he found professor Holmes so interesting. Instead of doing his assignments while listening to lectures, he would observe. He’d even sneak into lectures of other years just to try and figure the professor out.

Jim dressed into into a comfy t-shirt and trousers and sat down at his desk with a big cup of coffee. He booted up his computer and started by updating his firewall. He could fit in an hour before he had to go to his job. He was very tempted to do more digging into professor Holmes, but instead he indexed his projects. He loved his consulting. He would get emails with requests for jobs. Mostly from ordinary people, but sometimes he would be contacted by criminals as well. He’d put them in touch with the right people. For a fee of course. He’d write out plans for criminals. How to pull off heists or not get caught doing certain illegal things. Jim wasn’t terribly bothered by the knowledge that people would get hurt or die because of his plans. It would happen anyway, though less organized and people would get caught much more often. His plans, if followed precisely, would nearly always work out perfectly. He enjoyed his Mathematics, sure, but it was just a hobby, a way to pass the time when jobs were few and far between.

Time passed too quickly and too soon it was time for him to go to the bookstore. He changed into jeans and a dress shirt before racing to the bookstore on his bicycle. He cycled through the streets and came to a halt in front of the bookstore just as the owner arrived with the key.  
“Good morning Alistair!” Jim said cheerfully.  
“Morning Jim.” Alistair said less cheerfully.  
“Late night, was it?”  
“Ay.” he said “the poetry club did not want to leave.”  
“I’ll brew you a good strong coffee then.”  
“Cheers Jim.” Alistair said as he opened the door and went inside. By this time Jim had locked his bike to the racks at the front of the shop and followed him in. He went right to the back and brewed a strong cup of coffee for his boss, while his boss put some boxes from the back in the front.  
“These came in Thursday. They’re priced, so they just need to be put into the shop.”  
“Right-o.” Jim said with a smile as he handed Alistair the coffee and went to work. Jim was allowed to grab any books he wanted for the price Alistair had bought them (or Jim would take a book home, read it and /then/ put it for sale. Not that Alistair minded this). Jim quickly went to work, preferring having the books in before their usual Saturday crowd started to arrive. Part of this week's haul had apparently come from a deceased mathematics professor because Jim bought 12 books that morning, all about mathematics, cryptography and by Charles Dodgson.

His shift went quickly. He chatted with the usuals and the tourists and with Alistair. He mentioned the books to Alistair and before they knew it, they’d been discussing The Hunting of the Snark for half an hour (until they were cut short by a group of busy but friendly visiting students). Sooner than he realised his shift was over and he was cycling home again. Finally it was time to get back to work.

  
He brewed a pot of strong, sweet tea and sat down at his computer. When he looked up next the sun had long set and was on its way to rising again. Jim simply shrugged, brewed another pot of tea and started on his essay.

**Notes for the Chapter:**

> Next week: Mycroft's life


	6. Chapter 6

**Summary for the Chapter:**

> A view into Mycroft's day

It was six am on Saturday morning and Mycroft Holmes had finally solved an unfortunate crisis that he’d been called into late the previous evening. The head of MI5, Mycroft decided, would owe him a fair bit for this. Thankfully, everything was under control now and he could finally get a few hours of sleep.  
All too soon he had to get up again and grade some of the papers that he was supposed to be looking at the night before. He sat at his desk with a large cup of coffee and rubbed his eyes before he went to work.

All too soon he found himself distracted by one of his new students. He’d seen Jim Moriarty sneak into lectures he wasn’t supposed to be in and take a seat in the back. He’d pretended not to notice the young man, as he clearly did not want to be noticed. Jim Moriarty was a mystery to him. Moriarty had brought the facts logically and they’d checked out but it sounded /fake/ somehow. And to see him fencing and making contact like that at his club unnerved him. At the same time he felt a slight awe for the boy. He couldn’t deny that Jim was charming and clever and he could easily fool most of the world into thinking he was an innocent hardworking man.

Mycroft Holmes, however, wasn’t most of the world. He knew this and the people he consulted for knew this. Charm only was not enough to start working for some of the highest ranking members of the intelligence services of the country.  
He put his cup of coffee down, having made a decision, and opened the email program on his computer.

 

_Andrew,_

_It has been a pleasure working with you once again and I hope that you will still be joining for the members dinner coming Thursday. I also hope that the first edition I sent you last week has arrived safely and in time for your 4 year anniversary._

_I find myself in the unfortunate position of needing information on a student of mine and would consider it a personal favour if you could send me it as soon as possible. His name is James Moriarty, but he may also have used the name Jim Moriarty. I do not believe at this time that he would be a threat, but feel the urgent need to put my mind at rest._

 

_Kind regards,_  
_Professor Mycroft Holmes_

 

He sent the message and focussed on the papers in front of him once more. It did not last long, however, since fifteen minutes later a sound from his laptop announced that he had mail. He opened the reply from Andrew.

 

_Mycroft,_

_Your present arrived the very day, as you undoubtedly know._  
_The student in question has changed his name from James Moriarty to Jim Moriarty officially last year. He was born in Ireland to Cahir Moriarty and Kelly Brook but left after his father died in a fire. The father was widely believed to be a ruthless criminal, though no official proof exists. He was off the radar for a couple of years but surfaced last year when he started working at the bookstore he currently works at. I suggest asking Alex for some IRA files of his if you want to know more about his past. I see no immediate reason to be worried about him, but keep me in the loop if you think this warrants more research._

_I will indeed be joining on Thursday, the agency work permitting of course. Alex will undoubtedly be there as well._

 

_Kind regards,_  
_Andrew_

 

After a moment of thinking Mycroft decided against sending Alex an email at least for the time being. He wondered if Jim would make a good asset for either company and decided that he would rather see Jim go into the world of mathematics. Aside from facts, this was also based on a gut feeling that there was something dark in the young man or his past.


	7. Chapter 7

**Summary for the Chapter:**

> Jim gets in a tiny bit of trouble

Mycroft was working on a lecture in his office when his phone rang.   
“Professor Holmes.” he answered the phone. On the other end was another professor who clearly sounded very angry. Unsurprisingly, at least to Mycroft, the professor started ranting about Jim Moriarty. Jim, according to the colleague, had humiliated him in front of the whole class and insulted him. He demanded that Mycroft made sure it wouldn’t happen again or he would go to the dean and demand disciplinary action.   
Mycroft listened to the man and let him rant for a moment before assuring him he’d discuss it with Jim. 

He’d barely put the phone down when there was a knock on the door. “Come in.” Mycroft said in a stern tone.  
Jim opened the door and came into the office. He didn’t really look at Mycroft as he closed the door and played nervously with the strap of his bag. Jim made the effort to look like he felt guilty, but Mycroft saw straight through this act. He put some papers in a drawer and tidied his desk, letting Jim stand in the middle of the room. He wanted to see how long Jim could keep this act up without slipping. Jim however, was easily able to keep up the act for as long as he needed. When Mycroft had finished tidying his desk he looked up. His face was a mask of indifference.   
“Sit down, Moriarty.” he said coolly.  
Jim sat down on the chair and looked up at Mycroft expectantly.   
“Less than two weeks and you’ve already managed to anger a professor.” Mycroft said with disapproval in his voice, “and stop pretending you’re feeling guilty, it’s insulting.”   
Jim looked up in surprise and then smiled a little, just for a moment.   
“You’re right, professor,” he said as he shed the act. He understood that the act would only work against him with professor Holmes.   
“You’ll write a letter of apology to him.” Mycroft told Jim. “And you’ll hand it to him personally.”  
“But sir,” Jim started.   
Mycroft held up a hand to stop Jim from talking. “I was not finished, mister Moriarty. You’ll also thank me for letting you off easy.”   
Jim huffed annoyed, “and if I refuse?”  
“Then you are no longer welcome in his lectures and he may choose to go to the dean.”  
“Fine.” Jim answered annoyed, sounding much more like a child than he’d care to admit, and crossed his arms as he leaned back into the chair.   
Mycroft looked at Jim and shook his head, a little amused, and put a sheet of paper and a pen in front of Jim. “Start writing.”  
“I just pointed out a mistake he made.” Jim mumbled unhappily as he picked up the pen.  
“Yes, obviously.” Mycroft said with a soft chuckle.  
Jim looked up, surprised.  
“He’s quite incompetent and can’t take any criticism, but the others on his subject are even worse so I’m afraid you don’t have a choice. As one of his former students eloquently put it: suck it up and keep your mouth shut.” 


	8. Chapter 8

**Summary for the Chapter:**

> More of Jim's jobs.

Jim Moriarty was angry. Actually, angry didn’t quite cut it. Jim Moriarty was livid. He’d been at his gym when the email came and hadn’t seen it until he’d gotten home. Until then he’d been having a good day. He had won every fight at his mixed martial arts class and the adrenaline left him feeling great. It wasn’t until after he’d cycled home and showered that he checked his email and found out that someone had been caught and had _mentioned_ him. It didn’t say how much there had been mentioned or who’d heard it. He took just long enough to brew a pot of tea before getting to it and hacking the police system. He needed to get information. 

He wasn’t sure how much later it was when he looked up again, but he quickly realised it must have been a while since it had gotten dark. He made a fresh pot of tea and quickly ate two energy bars. He knew what had to be done to keep his business safe and so started calling in a few favours. He’d adjusted the documents and getting rid of the traitor was easy. What was more complicated is making sure there wasn’t any trace of it without raising suspicion. As he tried to figure that out, he sent the details of the man to an assassin who owed him a big favour and specified to make sure it was perceived as natural causes. 

In the end he settled for a mild amnesia drug in combination with something that mimicked a tummy bug. The man would be sick for a few days and lose all the details of the day before but wouldn’t do any real harm.   
Jim was tempted to go out and do the job himself, but rationally he knew it wouldn’t be any good. He’d got a professional to do it, someone who’d be far better at it. Besides Jim could not risk getting caught now. 

Before he knew it, his alarm went off. He hadn’t slept at all. He downed a strong cup of coffee and cycled to work.   
He was glad it was an early shift that consisted mostly of pricing books and making sure all the numbers in alistair’s carefully made excell sheets made sense. Jim, with plenty of coffee, got through it.   
“Jim?” Alistair asked as he put his hand on Jim's shoulder. Jim looked up a little shocked, having been absorbed by the page he was checking.  
“Yeah?” He asked as he tried to down more of his coffee, only to find it empty.   
“When did you eat last?”   
Jim blinked for a moment, trying to backtrack to his last meal. “Somewhere last night? I wasn’t really paying attention to the time.”   
“Another one of your energy bars, I suppose. Jim, I told you those aren’t enough for a meal. Especially not after MMA.” Alistair said, worried.   
Jim rolled his eyes “you’re making a fuss. Don’t.”   
Alistair rubbed his forehead with his hand in frustration. “Food is important, Jim.”  
Jim just shrugged as he turned his attention back at the computer screen.  
“I’m getting you a meal.” Alistair said. “And you’ll eat it all.” He sounded, to Jim, like a worried but kind father. Jim shrugged it off. The idea that someone could see him like their son seemed too fake. He turned his attention back to the computer screen, but ate the meal that Alistair put in front of him. 


	9. Chapter 9

**Summary for the Chapter:**

> One word: Chess

“What do you think?” Mycroft asked Jim when he’d finished reading a paper related to his other job. Jim had come in halfway through and Mycroft had told Jim he was busy for five more minutes, but to sit down. Instead of sitting down, Jim had gone to the chessboard in a corner of Mycroft’s office.   
“Well, sir,” Jim started, “white is looking a lot stronger than black. I think that white will win in less than ten moves, possibly less than five. I think that black is pretty much a lost cause.”   
“What would you do?”  
“Depends, sir.”  
“If you’re white and it’s your move.” Mycroft clarified.  
“If I were playing white, I would move my queen to G7, sir.”   
“You’ve played often, then?” Mycroft enquired.  
“Yes, sir, mostly on my computer.”  
“Care for a game?”  
“Always.” Jim said with a cheeky grin.   
Mycroft nodded at the chessboard. “Go ahead and set it up.”  
“And your game?” Jim asked.  
“Is one I’m playing with an acquaintance from Harvard. Over the internet, like yourself.”  
Jim nodded and quickly put the pieces back to the starting position. He saw Mycroft move some papers into a drawer and wondered, not for the first time, how much Mycroft did outside the Job at the university. He decided he would find out. When Mycroft had finished tidying his desk, Jim brought the chess set over and set it down on the table, white facing Mycroft. For a moment Jim was about to suggest they bet, but at the last minute he decided not to. It was too big of a risk and if anyone in the world could see through him, it would be professor Mycroft Holmes. He sat down opposite Mycroft and took out his all-purpose notebook. He wrote in his messy handwriting the date, the opponent and some other details. Mycroft had gotten a hand-bound leather notebook from a drawer and was doing something similar. 

Mycroft made the first move, as he played white. Jim replied the opening move with his own. There was silence in the room as both men moved the pieces and at the same time noted down their moves. Most of the game went quick, though both studied the board for longer occasionally. Jim was studying the board in one such moment, his brain almost completely focussed on the game, when he spotted the perfect opening and moved his piece. He kept his perfect poker face on as he did and then looked up at Mycroft.  
“How was the members dinner?”   
“Productive.” Mycroft answered as he moved his king. “Though as usual far too much banter and far too little actual fencing.”   
“I suppose,” Jim said as he moved his rook, “that is what happens when so many high-placed people gather. Check.”  
Mycroft moved his king away from the threat. “I suppose.”  
“But I will assume that it was a very informative evening for you.” Jim said with a soft grin as he moved his knight, “check.”   
“What makes you say that?” Mycroft asked, already knowing the answer, as he moved his queen between his king and the knight.  
“You’re not someone who,” Jim said as he moved his knight to take the queen, “will go to such gatherings if it’s not informative. Checkmate.”   
Mycroft smiled, laid his king on its side and looked at Jim directly. “You read people very well, James.”   
“So do you, professor.”   
Mycroft closed his notebook and put it in the drawer he’d taken it from. “It can be a very dangerous thing.”   
“I suppose you would know, sir.” Jim said with a somewhat cheeky grin.  
Mycroft observed Jim for a long, intense moment. “How would you like to see part of my other job, James?”   
Jim grinned softly, but proudly. “I would like that, sir.”   
“Be here tomorrow morning at nine sharp. Now out of my office, young man, I have work to do.” Mycroft said with a soft chuckle. Jim chuckled as well and, after quickly packing his bag, left. 

**Notes for the Chapter:**

> I still very much feel dead from cosplaying Jim yesterday, but thankfully I'd written this already early last week.


	10. Chapter 10

**Summary for the Chapter:**

> Jim visits Mycroft's other job

**Notes for the Chapter:**

> It's been a while since I updated this last. I lost my writing mojo due to some unfortunate circumstances. I have missed it a lot and I'm really glad to be back.

Jim had a pretty good idea of what Mycroft Holmes did outside the university work, but hadn’t actually had any proof for any of it. He decided he wouldn’t go in unprepared and spent the evening looking around the dark web for information about his tutor. Unsurprisingly, he found that Mycroft had a lot of fingers in a lot of pies. He made mental notes on what he found. The knowledge is usually there, if you just know where to look. Mycroft had, Jim knew, done his research on him as well. He wondered just how much Mycroft had figured out. If he knew about his parents, about his jobs….

 

After a good night sleep Jim had dressed in professional looking clothing and had managed to somewhat tame his hair. He checked his watch and found he was five minutes early. He cleaned his glasses, straightened his tie and checked the contents of his leather bag before he knocked on the door of Mycroft’s office.  
“Come in, James.” Mycroft said. Jim stepped into the office and waited by the door as Mycroft put a few files in his bag.  
“Good morning, professor.”  
“I see you managed to look presentable today.” Mycroft said as he let his eyes wander over Jim. He closed the bag and walked to the door, barely giving Jim enough time to follow as he made his way through the hallway and out the Mathematics building. Jim followed with ease anyway. A car was waiting for them. A car with a driver.

“I hardly need say that I expect you to do as you’re told.” Mycroft said with a cold undertone in his voice. “Ignoring orders can lead to prison really fast.”  
“I’m aware.” Jim replied, calmly. He wasn’t scared. Jim had been threatened before and by men far scarier than Mycroft Holmes or any government agent could be.  
Mycroft handed Jim a MI6 visitor badge as the car pulled up to Vauxhall Cross. Jim inspected it. He spotted four different security measures, one hidden under his portrait picture (which Mycroft had pulled from the school records). Jim clipped it to his breast pocket and followed Mycroft out of the car.

Inside the building Jim calmly went through security. His bag and phone went through the X-ray machine as he went through a metal detector and was patted down by a security officer. Mycroft, in the meantime was checking his phone with a rather disinterested look on his face. Jim said a polite ‘thank you’ when they handed him his bag and the visitor badge back. He joined Mycroft as they walked to the lifts. Before they could arrive there, a man stepped out and greeted Mycroft.  
“Good morning, Professor Holmes.” said the man Jim immediately recognized as the head of MI6.  
“James, “ Mycroft said “I’d like you to meet Alex Younger. Alex, this is James Moriarty.”

**Notes for the Chapter:**

> Hopefully I'll be back to mondays now. My motivation is still not where it used to be and this wobble is far from over so some encouraging comments would be much appreciated (sorry for asking, but I don't know if I'll be able to finish this without some encouragement)


	11. Chapter 11

**Summary for the Chapter:**

> Tea with Alex

_“James, “ Mycroft said “I’d like you to meet Alex Younger. Alex, this is James Moriarty.”_

“Good morning, sir.” Jim said with the tone he’d learned meant politeness and respect. “How do you do.”  
Alex Younger smiled “pleased to meet you, James. Professor Holmes has mentioned your excellent fencing.”  
Jim played slightly flustered, as if he found it embarrassing to be reminded of this. These kinds of places, these kinds of people, appreciated proper etiquette. Jim knew how to fake it. “Professor Holmes is a much better fencer, sir.” Jim said “As are you, undoubtedly.”  
“We shall have to see, won’t we?” Alex said with a grin.  
“I look forward to it, sir.”

Just because Alex and Mycroft were on a first name basis didn’t mean that he could. Jim preferred playing the quiet and obedient kind of person. Those kind of people appreciated it hugely. Flattery gets you a long way.  
Jim was dragged out of his train of thought by the notification sound of his phone. He took the phone out of his pocket and looked at the screen. The coded message might have looked like a normal email alert, but was in fact confirmation that the _little problem_ had been taken care of and wouldn’t come back to bite him. Jim didn’t show the relief he felt and turned his phone to silent and followed the two men to the lifts.

“There is currently a lot of interesting projects going on. We are changing the way the agency works.” Alex explained. They were sitting in Alex’ office with tea. The office had an amazing view and Jim was lucky enough not to sit with his back towards it. Not that he payed much attention to it, most of his focus was on the conversation and on the other two men in the room. “Of course I can’t tell you too much since you don’t have a security clearance. Yet.”

“I would be honored to work for you, sir.” Jim said with a smile that was mostly polite but had a proud grin hidden beneath it. He sipped his tea.  
“So what are the plans today?” Alex asked.  
“Today James will mostly be following me around.” Mycroft said before James could answer. “Of course I have arranged one or two tasks for him to put his skills and knowledge to good use and_”

Jim would never find out what came next as an alarm on Alex’ desk went off. All three looked up and in the direction of the sound. Alex took his phone out and started talking to whomever was on the line. He barked a few commands to the person and then hung up.  
“A slight problem has come up, Mycroft, which needs to be taken care of asap and I could use your help on this.”  
Mycroft nodded knowingly and rose to his feet. He then turned to Jim.  
“Stay here. Don’t touch anything.”  
“Yes sir.” Jim said quietly, as if slightly intimidated by it all.


	12. Chapter 12

**Summary for the Chapter:**

> Jim gets up to some things Mycroft would most certainly not approve of while he's alone in that office.

Mycroft and Alex Younger left Jim in the office. Jim heard the distinct click of the lock when they closed the door behind themselves. He was locked in. He briefly wondered if it was worth trying to pick the lock but decided that, no, it was not exactly a good idea. He put his, now empty, cup of tea down on the table and went to investigate the office. He walked over to the large desk and looked at the contents. Files were neatly locked away, but there was a stack of letters on one side. Next to it was a pot of green ink and an old-fashioned dip pen. Jim suppressed a chuckle. He assumed ‘C’ would be using a fountain pen with green ink. Apparently Alex liked a touch of the dramatic, but then again the service liked their traditions. He clanced at the letters and took a careful mental note of C’s handwriting and particularly his autograph. Next he focussed on the computer. It had two screens and looked very lovely to Jim. On it was a login page staring at him. Jim blinked. He’d expected some fingerprint login or maybe a keycard reader, but this seemed to just be a password. Passwords were breakable and often easily too, as Jim knew all too well. His computer and online accounts were carefully protected with randomly generated passwords, but people all too often didn’t and even if they did they often wrote them down.

Before he’d properly realized it, he’d sat down and typed a few commands onto the keyboard. It opened the login and Jim found himself looking around for the password. He lifted the keyboard to find the predictable note with a string of numbers and letters. Jim entered the code and was almost surprised to find that the computer accepted it. He now had access to the entire MI6 database. For a moment he wondered if this was the right thing to do, but then realized he was already way too far into it. In for a penny, in for a pound, as they say. He opened the mail application and found an email from Mycroft staring him in the face.

_Alex,_

_Thank you for the file. I am cautiously confident that Moriarty is not like his father and might become a great asset. I will bring him over to the office tomorrow._

_Mycroft_

 

Jim scrolled down to the message from Alex to Mycroft

_Mycroft,_

_I have included the file of Cahir Moriarty. While he was affiliated with the IRA, he seemed to have his own plans and business going that was far darker. Do note the lack of death certificate of his wife and the suspicions of our agent that Kelly Brook was murdered by her husband. There’s little mention of the young James Moriarty. I am confident to have heard back from our people who were involved if they could shed any light of it._

_Should I be added Jim Moriarty as a person of interest to any cases?_

_Alex_

 

Jim found the emails an odd mix between formal and informal language, but then again the ‘upper classes’ was not something Jim understood very well. He could mimic them, yes, but why they insisted on such odd traditions was above him.

Jim’s train of thought was interrupted by the lock on the door and the muffled sound of Mycroft and Alex. Jim logged off the system and put everything exactly as it was before. He sat back down in his own chair and took out his notebook and a half finished puzzle he’d found on a maths website. Mycroft and Alex walked in, both looking relieved to have dealt with the situation at present. As Alex closed the door, Mycroft’s eyes ran over the room and then went dark with anger. He knew.

 


	13. Chapter 13

**Summary for the Chapter:**

> “I better not find anything that doesn’t belong to you, James."

**Notes for the Chapter:**

> I almost forgot to upload it today as it's a bank holiday here. enjoy.

_ As Alex closed the door, Mycroft’s eyes ran over the room and then went dark with anger. He knew.  _

To Mycroft’s credit, he hid it well. Jim closed his notebook with a soft smile.  
“I hope the situation has been resolved, sir?”  
“Thankfully, yes.” Alex answered with a fond smile.   
“We must be going, James.” Mycroft said with a barely noticeable cold edge in his voice, but enough for both Jim and Alex to notice.  
“I suppose you better not be late for your next appointment, Mycroft. Give my regards to Lady Smallwood.”

Mycroft gave a short nod. Jim quickly rose from his chair and held out his hand to Alex. “It has been a pleasure to meet you, sir. I do hope that I will be calling you boss one day.”  
“With the right guidance, you might become a very good agent, and I do think that you have that opportunity. In the meantime I do hope to play against you some time at the club.”  
“It would be an honor, sir.” Jim replied.

“We do not want to be late, James.” Mycroft spoke as he opened the door. Jim hurried to Mycroft and followed him out. He kept close to Mycroft as he strode through the building. A casual observer might have thought that it was a high-ranked official and his PA or something similar, but to the both of them it was tense. Mycroft held a door open for Jim and Jim stepped inside an empty office. Mycroft closed and locked the door behind them and turned to Jim, “Empty your bag and pockets. Now.” Mycroft's voice left no room for argument. Jim, having nothing of the kind to hide, calmly and neatly placed everything from his pockets and bag onto the nearest desk. Mycroft kept a close eye on Jim.  
“I better not find anything that doesn’t belong to you, James. Face the wall, hands on your head.”  
Jim turned and faced the wall. He put his hands on his head, like he’d seen in the movies. He heard Mycroft inspect everything on the desk and then the bag. He turned to Jim and patted him down carefully. When he found nothing he took a step back.  
“Sit down, James.”   
Jim turned around and took a seat in one of the desk chairs.   
“Did you steal anything, James?”  
“No, sir.” Jim said. His voice was still calm but inside he felt scared. He wasn’t actually lying, he reminded himself. He hadn’t stolen anything.  
“I will not hesitate to have you locked up if I find that you are lying. I warned you in the car.”  
“I haven’t, sir. You made it very clear not to.”  
Mycroft calmed slightly “in that case, my apologies, James. You do understand I need to be careful, don’t you?”  
“Yes sir. I understand. Am I still allowed to follow you around for the day, or should I be going?”   
Mycroft watched Jim for a moment and considered his answer.   
“Yes. You are. Now pack your things.”  
Jim got up quickly and efficiently put everything back in his pockets and bag.   
“But,” Mycroft said with a small smirk, “you will owe me a favour for this. And you can be sure of it that I collect my favours.”


	14. Chapter 14

**Summary for the Chapter:**

> Things change for Jim

Of course Mycroft did not disappoint, even if he was angry with Jim. He’d taken Jim to a training facility to test Jim’s skills. Jim had the suspicion that Mycroft had arranged it while in the meeting before lunch where Jim had been forced to wait outside. Mycroft had grinned just a tad too widely when they’d gotten in the lift after lunch and announced that they were going to the training department. They ‘locked’ him in a cell in handcuffs and told him to get out and recover a USB drive. The handcuffs were relatively easy and he found the weakness in the lock soon after. The fight with the ‘guards’ had given Jim a few bruises and a cut on his face, but he had managed to get the USB drive and get to the designated safe area. To him it looked far too much like a computer game. He wasn’t going to complain, however, since it was far too much fun.

 

* * *

 

Just over two weeks later Jim was working another shift at the bookstore. He felt restless as he brewed two cups of strong coffee. He’d kept his other job to a minimum and done his homework like the good student he was. He sat down opposite Alistair.  
“What’s on your mind Jim?” Alistair asked after his first sip of coffee.  
Jim shrugged. “Uni and stuff.” he lied.  
Alistair looked him up and down. “What are they doing to you there? You look stressed.”  
“I guess i’m just swamped with homework.”  
“You look like you’re forgetting to eat again. Are you doing another one of your projects?”  
Jim glared at Alistair “No I’m not trying to solve P vs NP again.” *  
“You better not be. Maybe you should come over for supper again.”  
“I am fine, Alastair, really.” Jim reassured him.  
Alistair looked like he felt rejected, but said nothing.

The bell of the shop door went and Alistair went to look. Seconds later he was back, his face pale.  
“Jim, what did you do?”  
Jim looked up from his coffee, confused. “What?”  
“There’s police here. With a warrant for your arrest. What did you do?”  
“I’m sure it’s just a mistake, Alistair.”  
“Jim!” Alistair protested, getting more and more upset. “Don’t lie to me.”  
Jim rose from his chair and greeted the police officers. He asked for the warrant and read it over before nodding.  
“Don’t worry,” he said to Alistair “it’s just a mistake. I will call you soon enough.”  
He handed the warrant back and stood calmly as the police officers handcuffed him and read him his rights.

**Notes for the Chapter:**

> *p vs np is an unsolved mathematics problem in computer science and one of the seven Millennium Prize Problems. That means that the person who solves it will get 1,000,000 dollars (US).


	15. Chapter 15

**Summary for the Chapter:**

> being arrested should not be fun.

Jim tried his hardest to play frightened, but really he was excited. He’d never actually been arrested. Even so, he did play it well enough to fool the police officers that were arresting him. After they’d helped him (less roughly than Jim had expected) into the car, they mostly ignored him. They were trying to decide where to go for supper after their shift. Jim listened to the boring chatter while looking out the window.

Jim found the processing a very interesting affair. A good looking young police officer searched him and put everything he took off Jim in a white plastic tray. His phone, his watch, the coins from his pocket, his wallet, his earbuds and even his laces. He was photographed and they took his fingerprints with an electronic scanner. Jim continued to hide his excitement and play frightened.   
“What will your mother think, young man?” The woman who’d just taken his fingerprints asked. Jim looked up at her and saw all the signs of an unhappy wife in her fifties who’d lost a child. His eyes widened in well-played shock and the next second he looked like he was about to start crying.  
“Nothing, ma’am,” he whispered, “she’s dead.”   
The woman sighed a little sadly, “I’m sorry dear.”

The same good looking police officer as before escorted him to an interrogation room and handcuffed him to the table.  
“The detective inspector will be with you in a moment.”  
“Could I please have a cup of tea, sir?” Jim asked quietly.  
“I’ll see what I can do.” the police officer said with a soft smile that meant he would try for him.

With the give that the long chain in his handcuffs allowed, he took his glasses off and pretended to clean them with his shirt. Instead he snuck out the small piece of metal that was hidden in one of the legs of his glasses and pushed it into the teeth of the handcuffs. Soon he had the handcuffs off with the help of the shim. He moved the metal cuffs in a way that made it look like they were still fastened on his wrists. To the security camera it had looked like he’d been cleaning his glasses. He put the glasses back on again with the shim hiding in its usual place.

All in all it was less than fifteen minutes after Jim was guided into the room when the door opened again and Mycroft Holmes came in.  
“Good afternoon, mister Moriarty.” he said coldly and sat down. “Time to get started with this interrogation, don’t you think?”


	16. Chapter 16

**Summary for the Chapter:**

> Interrogations

**Notes for the Chapter:**

> I hadn't exactly realised I left it with a bit of a cliffhanger. I had the next chapter ready to go and then forgot to post it. But the good news is, I am writing again and will be uploading the rest of the story in one go when it's done.

_“Good afternoon, mister Moriarty.” he said coldly and sat down. “Time to get started with this interrogation, don’t you think?”_  
“Am I being charged with anything, mister Holmes?” Jim asked.  
“Not yet. Should we charge you with anything?”  
“I haven’t broken the law, so no.”   
“You are intent on playing this game, aren’t you?” Mycroft asked as he observed Jim closely.  
“Mister Holmes.. Mycroft. You’ve been an amazing tutor and I very much appreciate the introduction to C, but I’m afraid you’re seeing things that aren’t there.” Jim said with a convincing worry.  
“James,” Mycroft replied with a sigh, “stop this silly little thing. It’s insulting. I know you broke into his computer, I know you read the email regarding your parents. I know your little side-line business. Stop the facade.”  
“Then why are you still playing?” Jim asked, his voice colder and his Irish accent more pronounced. “Why are we here, playing this little game that you set up to try and scare me?”   
Mycroft couldn’t help it but smile a little, despite his annoyance. “I’m sure you can figure that out as well, James.”  
Jim grinned contently. Mycroft had no evidence. This was just him trying to intimidate Jim. It wasn’t working. Jim was having way too much fun and for once he didn’t hide it. Mycroft leaned back in his chair, annoyed.   
“I’m sure that attitude of yours might dampen a bit with a night in the drunk tank, James. Or a few days in prison.”  
Jim looked at Mycroft for a few seconds, “Now, what would Alex think of that?”   
“Oh it could be days, weeks even, before anyone finds the discrepancies in the papers, and even then they won’t lead back to me.”  
“Are you threatening me, mister Holmes?”  
“Nothing of the sort, mister Moriarty, just telling you how our system is these days.” Mycroft said, instantly having switched back to a fake pleasant tone of voice.  
“In that case, I think it best if you just let me go, don’t you? Since you can’t prove I did anything wrong.” Jim said as he mimicked the same pleasant tone and flicked his wrists so that the handcuffs slid of them and fell on the table with a loud clang.  
Mycroft stared at at the handcuffs and then at Jim for a few seconds in surprise. He then sighed, “very well then. Don’t forget you have an essay to turn in two days from now. I expect you in my office at ten. Am I clear?”   
“Crystal clear, professor.”   
Mycroft rose and walked to the door. He opened the door and Jim followed him out. Mycroft turned to the good looking police officer. “Kindly return mister Moriarty his property and escort him out the door.”

**Notes for the Chapter:**

> I hope to have finished the story in a week or two and will upload the rest in one go.


	17. Chapter 17

**Summary for the Chapter:**

> getting personal

After getting his belongings and being escorted out of the building Jim first bought himself a large cup of coffee. He needed to think properly. If he wanted to get out of this mess he needed to outsmart Mycroft Holmes. He needed a way to ensure Mycroft would not share what he knew about him and preferably without killing the professor. He walked aimlessly through the streets for several hours, nursing his cup of coffee, until he found himself in front of the bookstore. The shop was supposed to be closed up already, but the light was still on. Jim tried the door and found it was open. He walked in, only to hear Mycroft in the middle of a sentence.  
“.. to have to tell you this, but we found it only fair since it concerns valuable items. We thought we should inform you.”  
Jim came around the corner. Alistair had sat down, pale as a sheet, and Mycroft was standing there with a fake sympathetic look on his face. Jim’s fists balled in anger. He took a deep breath and stepped into the light.

“What are you doing here, professor?” He asked and then, as if he just saw Alistair’s face, “What’s happened?”  
Mycroft’s face was neutral but cold.  
“Your professor has told me what happened at the club you fence at. I can’t believe.. Jim. bloody hell Jim. Never took you for a thief.”  
Jim looked at Mycroft, shocked, “what did you tell him?”  
“We only found it fair to inform your boss of your behavior, James. Stealing something that valuable is very serious.”   
Jim turned to Alistair, “you can’t possibly believe him!” he said pleadingly, “please. You know me. I wouldn’t do that.”  
“You were arrested!”  
“I’m here now. They wouldn’t have let me go if they still suspected me.”   
“Oh for fucks sake Jim!” Alistair yelled angrily. Jim stepped back. He’d never seen him angry like that.  
“Alistair…” Jim pleaded, “please.. I’m sure there’s a perfectly logical explanation to all this.”  
“You’re fired.” Alistair said angrily.  
Jim’s heart sank. Until that very moment he didn’t realize how much the book shop owner meant to him. He didn’t even have to fake the tears that were running down his face.  
“You-you don’t mean that.”  
“Get. Out. Of. My. Shop.”Alistair growled and threw Jim's bag at him.  
Jim caught his bag without really thinking about it and walked out the door.


	18. Chapter 18

**Summary for the Chapter:**

> no way back

Jim was seething. Mycroft had made it personal, well, so could he. Before he knew it, he stood in front of the mathematics building. He was about to go in when he stopped.   
_Never do things out of anger._  
It was a lesson his MMA teacher had taught him but it was a good one for his life and business as well.  
 _In anger you don’t think clearly, in anger you make mistakes._  
At first it sounded like a line from a bad ninja movie, but it was true. Jim had known it instinctively to work in other people. He turned around and went home. Once home he loaded up the most violent first person shooter game he could find and played for a few hours, the noise of the gunfire loud in his headphones. While shooting computer generated bad guys, he played the problem over in his head.   
Three hours later he’d figured out what to do. He closed down the shooter game and spent another hour arranging things online before catching a few precious hours of sleep.

 

He woke early the next morning and packed his stuff. After getting a final few things ready on his laptop he took his bag and his fencing bag and headed to Mycroft’s office. On his way he printed his essay and he arrived a few minutes to ten. He knocked and waited.   
“Come in.” Mycroft’s voice came from inside. Jim took a deep breath to steady his nerves and went in. Mycroft sat at his desk wearing a dark three-piece suit.   
“Good morning, professor Holmes.” He said calmly as he put his essay onto the desk.   
“Have a seat, mister Moriarty.” Mycroft said with a cold undertone in his voice. Jim did so. Even to Mycroft he seemed calm, his mask perfect. Mycroft looked through the essay, his focus more on Jim than on the essay itself.   
“Got anything to say, mister Moriarty?”   
“As a matter of fact, I do sir.” Jim spoke calmly. “I would like to challenge you to a fencing rematch.”   
“And why would I be inclined to agree?”  
“We could have another bet.”   
“What would be in it for me?”   
“Two questions. Off the record. And my word that I will answer them honestly.”  
“And if you win?”  
“You listen to me for five minutes.”   
Mycroft observed Jim for a long moment. “You have yourself a bet. Epee. five points. The club at two pm.”   
“Very well.” Jim said with a hint of a smile on his face. “I will see you there.”


	19. Chapter 19

**Summary for the Chapter:**

> Fencing, again.

The club was closed but the back door was open. Jim arrived fifteen minutes early and changed into his fencing uniform. He waited in the hall they’d fenced at the first time, knowing that’s where Mycroft would be. And as Jim had expected, Mycroft showed up at exactly two pm.   
“Good afternoon, mister Moriarty.”   
“Good afternoon, professor Holmes.” Jim said as he held out his hand. Mycroft shook it. They both went to their spots. Jim checked his equipment quickly and then looked up at Mycroft. Mycroft held his sword in front of his face as a greeting and Jim did the same.   
“En garde.” Jim said calmly. He put his mask on.  
“Pret.” Mycroft said as he did the same.  
Jim stood confidently with his epee in his left hand, ready to start “Allez!”

Mycroft was first to attack, confident and almost aggressive. He was clearly eager to get this over with. Jim defended expertly, but Mycroft managed to get his first point in anyway.  
“Touch.” Jim called.   
Mycroft stepped back and gave Jim a moment to breath. Jim nodded after a few seconds and Mycroft attacked again. This time, however, Jim got the perfect opportunity for a parry-riposte and took it.   
“Touch.” Mycroft hissed. Jim stepped back but as soon as Mycroft nodded he came in with a hard attack on Mycroft’s backhand. Jim wondered if it was still the weakest of Mycroft’s fencing and was unsurprised that even though he’d clearly been training, it still was. Soon after, Jim scored another point. Mycroft hardly gave Jim a moment to collect his thinking and went right back into a fiery attack. Jim kept up with it. He was ahead now. Just that moment Mycroft had found an opening in his defence and hit Jim.  
“Touch.” he said more calmly than he felt. It was now two all.   
Mycroft took a moment longer to recover this time and Jim let him have it. He needed it as well. Mycroft started the attack again, but Jim scored yet another point.   
Three to two.   
They continued almost immediately and Mycroft scored another point.  
Three to three.   
Again, Mycroft gave Jim no chance to catch his breath and continued. He scored another point against Jim.  
Four to three. Another point for Mycroft and Jim would lose. He had a plan for losing but winning this game would make everything a lot easier.  
Mycroft was getting tired. Jim could tell. His moves were slightly less coordinated and just a fraction slower. Jim played relentlessly on Mycroft’s backhand until he scored another point.  
Four to four.   
Mycroft pulled his mask off. Jim, surprised, did the same.  
Jim bit back a rude comment and waited for Mycroft to speak. Mycroft was, beneath the coldness on his face, angry.  
“Since having a duel is so by traditions, let's put another into practice.”  
“What do you propose?” Jim asked curiously.  
“Sharp epees and the final point goes to whom first draws blood.”  
“That’s awfully _James Bond_ of you, professor.” Jim said with a grin. “I like it.”  
Jim pulled his fencing jacket off and followed Mycroft to a display case to the side. Mycroft opened it and gestured for Jim to pick. Jim inspected both while Mycroft took his own fencing jacket off. He, like Jim, was wearing a well-fitted white t-shirt. Jim picked the epee with the simpler handle and observed Mycroft as he took the remaining epee from the display case. Mycroft looked fitter than Jim had previously thought. Those suits must have something to do with it. Jim filed away the thought for later and spent a moment getting a feel for the epee.

Mycroft held the sword in front of his face as greeting. Jim copied.   
“En garde.” Mycroft said with determination.  
“Pret.” Jim replied with the same determination in his voice.  
“Allez!” Mycroft called and attacked Jim. Jim blocked quickly and efficiently. The sharp epee felt different in his hand, but it wasn’t hard to get the hang of it. It felt oddly natural.   
Jim got the feel for it more and more and attacked more viciously. This wasn’t just a soft touch, not he needed to make it count.   
Suddenly he saw the perfect opening. Again it came from the weak spot in Mycroft’s backhand. He moved in and made a five centimeter shallow cut in Mycroft’s upper right arm, just under the hem of his sleeve.   
Mycroft hissed, half in annoyance, half in pain.   
Blood started to slowly trickle from the wound. Mycroft contained his anger expertly as he put his epee down and held a piece of cloth against the cut.   
“Congratulations mister Moriarty.”  
Jim carefully cleaned his epee while he kept half an eye on mycroft, who was putting a bandage over the cut.


	20. Chapter 20

**Summary for the Chapter:**

> agreements

“This way, mister Moriarty.” Mycroft said after a few minutes of silence as he pointed to the president's office. Jim followed Mycroft inside and was unsurprised to saw two cups waiting next to a pot of tea. He poured the tea in the cups and sat down opposite from Mycroft. Mycroft took his phone out and set a timer for five minutes.   
“Make it brief, mister Moriarty.”  
Jim nodded and took a sip of his tea while giving Mycroft a second to press the button for the timer. He took a deep breath and started speaking.  
“I think we both know how this can go and how badly we can play this but we will end up ruining each other's careers and possibly lives in the process so instead I suggest a truce. I move away from this city and you allow me to start over. You keep what you know about me and my job to yourself. I won’t make this personal and neither will you.”  
Mycroft blinked for a moment, he hadn’t seen this coming.  
“What makes you think this is a good offer for me, then?” he asked, though he was already pretty sure he knew the answer.  
“Because, unlike me, you have a family that’s still alive.”   
“How will I know you keep to your part of the deal?”  
“Surely I don’t need to explain that to you?”  
Mycroft considered this for a moment. “Very well. I have one other request.”  
“I will ask for something in return.”

“I will give you the uncensored files on both your parents if you tell me why you started in crime.”  
Jim thought about this for a moment. “Very well. Now practically. I want 24 hours to leave here safely.”  
Mycroft nodded. “Then it is a deal.”

Jim took another sip from his tea, this time more slowly, and thought for a moment about his words before he started talking.  
“It started more or less out of necessity. I was broke, on my own and hungry when I first came here. Official jobs obviously wouldn’t take me on and I couldn’t go to foster care because bad people were looking for me there. But I had a laptop and I’m good with computers and it sort of went on from there.”  
“Why don’t you get out then? Now you can?”  
“You know as well as me that in our line of work the only way you leave it is in a body bag.” Jim said coldly. “Besides…” he said as he began to smile “It is fun.”   
Mycroft observed Jim for a few seconds, trying to read the consulting criminal, before straightening his back and going back to the demeanor Jim had seen at MI6. He reached into the bag that had been standing next to his feet and took two paper files out of it. He put them on the table so Jim could see the names ‘Cahir Moriarty’ and ‘Kelly Brook’ on them.   
“You have 24 hours to get out of town, James. I suggest you make use of your time.”   
Jim held out his hand. “Professor Holmes, all in all I have learned a lot from you and I wish you the best in your career at the university.”  
Mycroft shook his hand. “You have been a very promising student, mister Moriarty.”  
Jim smiled, just for a moment, before he picked the files up from the table and left.

 

As Jim drove out of town the next morning he thought about what he’d read in the files. How his mum was recruited to spy on his father, how she’d said that she thought he was on to her just before she disappeared.   
He’d pinned the photo of her he had found in the file to the dashboard and smiled “Don’t worry mum,” he whispered “I got back at the bastard.”


	21. epilogue

**Summary for the Chapter:**

> years later

“Good afternoon, professor Moriarty.” came a smooth, educated voice from the back of the lecture theatre. The students had left and Professor Jim Moriarty had thought he was alone. He recognized the voice at once and looked up from the papers he’d been sorting after his lecture.  
“Good afternoon, professor Holmes.” he said while he looked over the professor opposite him.  
“I see you managed to finish your degree after all.” Mycroft Holmes said as he nodded to the blackboard behind Jim. “And on computational number theory of all things. Though I am hardly surprised you took that particular subject with your background in hacking.”  
Jim smiled as he put his laptop and papers in his bag. “Could I invite you for a cup of tea in my office, professor?”  
“I’d be delighted.”  
“This way.” Jim said as he started walking to the door.

Mycroft spent another moment looking at the blackboard before following Jim. They were silent as they walked to the office. Two walls of Jims office were filled with books, a third was a full-wall blackboard and there were windows in the fourth wall. Among the books, which were on all kinds of subjects, were little trinkets and trophies.

“Still fencing, I see?” Mycroft asked when he inspected a trophy while Jim made tea.  
“As always. Still milk and one sugar?”  
Mycroft nodded as he continued to look around the office. Jim poured the tea and sat down in his chair. Mycroft took this as his cue and sat down opposite Jim.  
“Why are you here, Mycroft?” Jim asked after he’d taken a sip of his tea.  
“Can’t a professor check up on his former student?”  
“We had a deal, Mycroft. We managed to keep to it for all these years, so what’s changed?”  
“How is Alistair?” Mycroft asked instead of answering the question.  
Jim gripped his cup a little tighter. “Dead, as you well know.”  
“You didn’t really think you could have personal attachments as a criminal, James?”  
“Says the person who had two loving parents growing up.” Jim said bitterly, for once not hiding his emotions.  
“Do you know why I kept to my word, James? To leave you alone.”  
“Because I would have destroyed little Sherlock if you didn’t.”  
“Hardly.” Mycroft said “It is because you could have attempted to right away, but you controlled your anger and did what was best for your future.”  
Jim frowned but didn’t speak.  
“I was and still am hugely impressed and I knew in that moment that you would make the criminal world a better one, as far as that’s possible.”  
“They say flattery will get you anywhere, Mycroft. What do you really want? You didn’t come here to talk about number theory or catch up with a former student.”  
“It is the truth, James, and I was right back then, but you’re also correct on this. I need a favour.”  
Jim observed Mycroft for a long moment, seeing how Mycroft was quite nearly desperate in whatever situation he was in and how he would do almost anything to solve it.  
“Elaborate.” Jim said curiously  
Mycroft took another sip of his tea before speaking “It concerns my brother……”

**Notes for the Chapter:**

> oh my gosh it's finally finished. I'm glad I've finished it. It's been hard to write when posting chapter by chapter but it has certainly been an interesting experiment. you can clearly see my writing has improved over the chapters (I think so anyway).  
> thank you for sticking with Jim and Mycroft to the end. I hope you enjoyed it.

**Author's Note:**

> many many many thanks for my amazing beta disgvises.


End file.
